Trade-offs between growth and reproduction in a long-lived plant

(1)

Trade-offs between growth and reproduction

Valentin JOURNÉ, Hendrik DAVI, Emily WALKER, Etienne KLEIN, François COURBET, Francois LEFÈVRE, Sylvie ODDOU-MURATORIO, Julien PAPAÏX

Example with a long-lived plant

PhD Student, INRA URFM, Avignon

Wed, 22 August

S-69 Evolutionary Physiology

(2)

Acknowledgements Funding:

Collaborators:

(3)

survival

growth

reproduction

Context

Physiological and

genetic constraints

(4)

survival

growth

reproduction

Context

Adapted from Cody 1966

Reznick, 1983

What is trade-off ?

(5)

survival

growth

reproduction

Context

Reznick, 1983

(6)

survival

growth

reproduction

Context

Adapted from Cody 1966

Reznick, 1983

(7)

Context

Reproduction

Growth

individual a

Reproduction

Growth

individual b

a

reproduction

growth ^b

(Reznick, 1985; Reznick et al., 2000; Roff, 2000)

How to measure trade-off between growth and

reproduction ?

(8)

Context

Reproduction

Growth

individual a

Reproduction

Growth

individual b

a

reproduction

growth

Difficulties to estimate resources … variation between years and individuals

b

<

>

Resources

(9)

Context

Resources = energy (Carbon, Nitrogen, Water...)

Stearns, 1989; Zera & Harshman, 2001 Biotic factors

(interaction)

Abiotic factors (climate...)

Need to integrate physiology

(10)

Context

Bayesian approach

Hierarchical model

Unobserved variables

Direct correlation estimation

Roff & Fairbairn, 2007; Worley et al., 2003

Resources = energy (Carbon, Nitrogen, Water...)

Stearns, 1989; Zera & Harshman, 2001 Biotic factors

(interaction)

Abiotic factors (climate...)

(11)

Material and Methods

●

The species :

Cedrus atlantica

●

Conifer

(12)

Material and Methods

Patterns of resource allocation during reproduction

Male

reproduction Female reproduction

Cones

initiation Pollination Female cone

Maturation

J F M A M J J A S O N D J F M A M J J A S O N D

Year n Year n+1

(13)

Material and Methods

Sault

(14)

Material and Methods

Sault

~ 100 km

*Boy ! A Marseillaise-style RICARD

(15)

Material and Methods

1200 stems/ha = high density

Plantation with two density populations

250 stems/ha = low density

Even aged populations !

(16)

Material and Methods

Observation during 4 years

Female cones quantity

high density low density

(17)

Material and Methods

Observation during 4 years

Female cones quantity Male pollen index

(18)

Material and Methods

Observation during 4 years

Growth increment

(19)

Material and Methods

Observation during 4 years

Female cones quantity Male pollen index Growth increment

Reproduction Growth

(20)

Material and Methods

Year n Year n+1

Process

(21)

Material and Methods

Climate DBH

Tmean Precip Size_i

Growth_i

Cones initiation_i

Females cones survival_i

Year n Year n+1

Process Resources_i

+ δ_i

p 1- p

(22)

Material and Methods

Climate DBH

Tmean Precip Size_i

Growth_i

Cones initiation_i

Year n Year n+1

Process

Resources_i Climate DBH

Tmean Precip Size_i

Resources_i

+ δ_i + δ_i

p 1- p

(23)

Material and Methods

Climate DBH

Tmean Precip Size_i

Growth_i

Cones initiation_i

Year n Year n+1

Process

Data Growth

Increment_i

Male pollen index_i

Female cones_i

Tmean Precip Size_i

Resources_i

+ δ_i + δ_i

p 1- p

(24)

Material and Methods

Climate DBH

Tmean Precip Size_i

Growth_i

Cones initiation_i

Year n Year n+1

Process

Data Growth

Increment_i

Male pollen index_i

Female cones_i

Tmean Precip Size_i

Resources_i

+ δ_i + δ_i

p 1- p

(25)

Material and Methods

●

Growth

_i,n

= γ * Resources

_i,n

+ ε

_1,i

●

Cones Initiated

_i,n

= X

_i,n

* ( β

₁

* Resources

_i,n

+ ε

_2,i

)

●

Females cones survival

_i,n

= β

₀

+ β

₂

* Resources

_i,n

+ ε

_3,i

Allocation of resources to 3 energetic sinks

X: Probability to reproduce

ε

: Residual term

(26)

Material and Methods

ε

_1,i

ε

_2,i

ε

_3,i

~

Multivariate Normal (0, Σ)

σ_1,1

σ_2,2

σ_3,3 σ_2,3

σ_1,3 σ_1,2

... ...

...

_ρ_x,y ^σ^x,y

σ_x,x

*

^σy,x

=

Define correlation coefficient

Estimation of trade-off

(27)

Results

Effects of Climate and Size on resources

Size

Precipitation Temperature

(28)

Results

Resources vary among years and competition levels

estimated observed

(29)

Results

Negative correlation between Growth and Cones initiated

●

Growth

_i,n

= γ * Resources

_i,n

+ ε

_1,i

●

Cones Initiated

_i,n

= X

_i,n

* ( β

₁

* Resources

_i,n

+ ε

_2,i

)

= -0.63

Prob[ρ_1,2<0] = 0,95

ρ_1,2

high low

ε

_1,i

ε

_2,i

(30)

Results

Positive correlation between Growth and Female cones survival

●

Growth

_i,n

= γ * Resources

_i,n

+ ε

_1,i

●

Females cones survival

_i,n

= β

₀

+ β

₂

* Resources

_i,n

+ ε

_3,i

= 0.34

Prob[ρ_1,3> 0] = 0,82

ρ_1,3

high low

ε

_1,i

ε

_3,i

(31)

Results

Negative correlation between Cones initiated and Female cones survival

●

Cones Initiated

_i,n

= X

i,n

* ( β

1

* Resources

_i,n

+ ε

_2,i

)

●

Females cones survival

_i,n

= β

0

+ β

2

* Resources

_i,n

+ ε

_3,i

= -0.84 Prob[ρ_2,3< 0] = 1 ρ_2,3

high low

ε

_2,i

ε

_3,i

(32)

Discussion

1) Clear trade-off between growth and reproduction at initial stage (negative correlation)

2) Positive variation of growth and cone survival (positive correlation)

3) Current year of reproduction impact future

reproduction (negative correlation)

(33)

Discussion

1) Clear trade-off between growth and reproduction at initial stage (negative correlation)

2) Positive variation of growth and cone survival (positive correlation)

3) Current year of reproduction impact future reproduction (negative correlation)

➢

Same trend for both populations: density did

not impact all three relations identified

(34)

Discussion

Several hypothesis exists (e.g. resource

matching, resources switching...)

(Kelly & Sork, 2002;

Pearse et al, 2016)

growth

reproduction

Current reproduction Future

reproduction

Not only one hypothesis

Why trees produces variable quantities of seeds?

(35)

Discussion

➢

Evolution is needed to understand

ecological phenomenon : Why trees produces variable quantities of seeds ?

➢

Mechanistic approach for trade-off

investigation : a touch of physiology allows a

better understanding of evolution

(36)

Discussion

➢

Growth Increment drives the level of resources

➢

How to simulate resources?

➢

Integration of more physiological process?

Variation of resources : depending of climate,

tree size and density

(37)

Discussion

Comparison of resources estimated with an ecophysiological model

Dufrêne et al., 2005

(38)

- We combined physiology and evolution

- We found evidence for growth-reproduction trade-offs in trees

More information ?

@Valentin_Journe Valentin.journe@inra.fr

(39)

●

Initialized Males cones

_i,t

= Phenotypic gender

_i,t

* Initialized cones

_i,t

●

Notations convert into Multinomial observation

Supp

(40)

●

Initialized Males cones

_i,t

= Phenotypic gender

_i,t

* Initialized cones

_i,t

●

Notations convert into Multinomial observation

●

Link Initialized Males cones (observed) to latent

variable Initialized Males cones in the process model

Supp

(41)